SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ef66ac55c8b23aa2392bdd2eece9b1332d04c1d1a46e113bfbf3f61f1e6819ca' 
  AND token = 'Wacbn2wTQc5rCFfnnr8kSMaZZWr1LYDpfayt3uBKXyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}